Messages in this thread | | | Date | Tue, 4 Dec 2001 14:20:47 +0100 | Subject | Re: tuning ext2 or ReiserFS to avoid fragmentation with large files? | From | (Erik Tews) |
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On Mon, Dec 03, 2001 at 02:13:22PM +0100, Roy Sigurd Karlsbakk wrote: > hi all > > I've got this server with lots of ~3GB files and every now and then we > need to add some more or delete some old ones. All files are potentially > read concurrently, so to reduce disk seeks, I've increased the readahead > settings in kernel (/proc/sys/vm/(min|max)-readahead). > > Then... A friend of mine told me I could tune the fs (or vfs) to allocate > n kB each time a file is created, and by setting this to whatever I've set > (min|max)-readahead to (currently 1048576), I will reduce the negative > effect of fragmentation to a minimum, since the data blocks will be large, > and read more-or-less sequencially. > > Can anyone tell me how to tell the fs or the kernel to allocate n pages/kB > this way? Is it possible? Can I possibly set different sizes per file > system?
If I remember right xfs has got a online-defragmentation utility. So have a look at xfs.
I think xfs works different from reiserfs and ext2 when writing files to disk which helps avoiding fragmentation. This feature is called allocation groups. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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